Stomach Pain Quiz: Nausea & Other Causes

There is variation among people in their bowel habits and in what's considered normal. The frequency of bowel movements in healthy people varies according to age, diet, and activity level.

The small intestine is the area in which most digestion occurs. In the first part of the small intestine (duodenum), food from the stomach is mixed with bile from the gallbladder and enzymes from the pancreas that help digest food.

After leaving the small intestine, food is passed into the large intestine or colon, where water is extracted. The remaining material passes out of the body as stool or feces.

The length of the small intestine is approximately 22 feet. The large intestine (colon), in contrast, is only 5 feet in length.

Passing gas is quite normal, and healthy people can pass gas around 13-21 times a day. Foods that lead to gas in one person may not have the same effect in other people. Passing gas with greater frequency than this might suggest a problem with digestion of some type of carbohydrates.

Gastroenteritis caused by viruses is referred to as the "stomach flu", but this is not the same as true influenza caused by the influenza viruses. Viral gastroenteritis is contagious from person to person and can be spread by contaminated surfaces, hands, air droplets, or food and drink.

The spleen is an organ in the upper left quadrant of the abdomen that serves to filter the blood. It is not part of the digestive system.

Emesis is the medical term for vomiting, or expulsion of the stomach contents through the mouth. Vomiting typically follows nausea and is an automatic behavior that occurs in response to stimulation of a specific region of the brainstem known as the vomiting center.

Gastroesophageal reflux disease, or GERD, is sometimes referred to simply as acid reflux. In this condition, acidic stomach contents pass backwards up into the esophagus.

Probiotics are living microorganisms that are ingested for the purpose of health benefits. Probiotics can include foods like yogurt, supplements, and some kinds of topical products such as creams. Many bacteria have health-promoting effects, such as the bacteria normally present in the intestinal tract that aid digestion. Many of the organisms in probiotics are similar to or the same as those that occur naturally in the body.

Ulcerative colitis and Crohn's disease are both inflammatory conditions of the gastrointestinal tract. Ulcerative colitis affects the large intestine (colon) only, but Crohn's disease can affect any location in the gastrointestinal tract.